Triple-expansion engine



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M. T'; DAVIDSON.

TRIPLE EXPANSIDN ENGINE.

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Patented Jan. 171, 1888.

(No Model.) Y

` M. T. DAVIDSON.

TRIPLE EXPANSION ENGINE.

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MENEM.

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UNITED STATES MARSHALL T. DAVIDSON, OF BROOKLYN, NEV YORK.

TRIPLE-EXPANSION ENG-INE.

SPECIFICATION forming part of Letters Patent No. 376,639, dated January 17,1888.

Appfration filed April 9, 1887.

.To CLZZ whom z'z may concern:

Be it known that I, MARSHALL T. Dri-vinsoN, a citizen ofthe United States, residing at Brooklyn, Kings county, New York, have invented certain new and useful Improvements in Triple- Expansion Engines, of which the following is a specication.

My invention relates to that class of steamengines in which the exhaust-steam from a high-pressure engine or cylinderis used expansively in another cylinder; and my invention consists in providing the engine with three cylinders axiallyiu line, and in supporting and arrangingsaid cylinders, and in connecting the valves and otherwise constructing the engine so as to increase its efficiency and facilitate its construction and operation. Y

In the drawings, Figure l is a sectional side elevation ofa compound pumping-engine embodying my invention. Fig. 2 is a plan View. Fig. 3 is a sectional plan.

The bed A of the engine has a support, B, for the central low-pressure cylinder, C, of the engine, and when the engine isa pumpingengine the bed also supports the pump-cylinder, (not showm) but when the latterA is not employed the pillar-blocks of the enginecrankshaft may be arranged upon the bed.

The rear head, 1, of the cylinder C is bolted in place, as usual, and to the said head is secured a bracket, 2, bolted at the outer end to the inner head of a high-pressurecylinder, E, which is thus supported by and in linewith the cylinder C and independently of the bed.

To the forward head, 3, of the cylinder C is secured another but smaller low-pressure cylinder, F, the high-pressure cylinder E and the twolow-pressure cylindersbeinginline axially, and the central cylinder thus supporting both of the other cylinders. All of the cylinders are of the same length.

The cylinder F is provided with a piston, 4, and central piston-rod, 7, connected to or carrying a crosshead, g, afnd to the latter are attached the two parallel piston-rods 8 8 of the piston 5 of the middle cylinder, C, which eX- tend through packing-boxes on that part of the head 3 which is outside the periphery of The piston 6 of the high-pressure cylinder E is connected by a rod,

l0, axially arranged,with the piston 5 of the Serial No. 234,273. (No nodel.)

cylinder C, so that all the pistons move in unison and have the saine stroke.

The cylinders F C E are provided, respectively, with valve chests 12 13 14 and with suitable valves and ports, and the exhaust-port of the high-pressure cylinder E is connected by a pipe, 15, with the inlet-port of the forward chest, 12, and the exhaust-port ofthe latter is connected by a pipe, 16, with the inletport of the central chest, 13, and the valves are so con trolled that the steam, after doing its work in the cylinder E,-is exhausted into the forward cylinder, F, and there further expands and acts to move the piston 4, and after its escape from the cylinder F it further acts upon the piston of the largest cylinder C. By this construction I secure a drectlacting triplevexpau sion engine with all the cylinders axially in line.

As the high-pressure cylinder is supported by the bracket 2 at a distance from the middle cylinder, easy access may be had to thestuii'- ingboxes of both cylinders, and the cylinder E can be disconnected without disturbing the other parts of the engine,while the forward cylinder, F, can be removed and replaced without changing the position of the central cylinder, and as the latter only is directly connected with the bed-plate, the removal of the other cylinders does not necessitate any altera tion in the bed-plate connections.

W`hile any suitably constructed and connected valves may be employed, I prefer to operate one valve from the other. Y

In the construction shown the valve of the forward cylinder, F, is operated by steam pressure controlled by a rock-shaft, 17, as in the valve patented February 12, 188i, No. 293,243.

The valve-rod 1S of the cylinder Fis connected to and operates the valve of the cylinder C, and a valve-rod, 19, from the latter valve is connected to operate the valve-rod 20 of the high-pressure-cylinder valve.

When itis desired to vary the throws of the valves-as, for instance, to use a valve with shorter stroke on the high-pressa re cylindere I construct the connections to secure this re sult. Thus the valve-rod 19 is connected by a link, 2l, to a lever, 22, pivoted to the bracket 2 at the lower end, and connected by a link,

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yot the initial engine being moved freni that of the secondary engine, and the stroke of either may, by like means to those described, be varied from that ot` the others to any extent desired. The prime mover, however,of t-he val vemotion can be operated from either valve chest, as is obvious.

The engine, it'loaded, could not be started from a state ol' rest by admitting the high pressure only to the initial or high-pressure engine. l therefore connect the steam inletpipe 29, (which communicates with the valveehestlflandhasthensualthrottle,80,)byapipe, 3l, provided with a valve, 32,with the exhaust port or pipe ol' the cylinder E, so that by opening the valve 32 the steam maybe directed under full pressure to the secondary cylinder F, and after the engine is started the steam may be cnt oll` directly from the secondary cylinder and admitted to the cylinder E.

Live steam may be admitted to any one or more of the cylinders when starting by the introduction ot' suitable passover valves connecting all or any of the cylinders, as is ap-` parent. Y

Then it is decided to work two of these triploexpansiou direct-acting engines in donble or duplex l'orm, the valve-n1otion will be operated and the service of the pumps, il the struction and arrangement of parts shown, I

claim- 1. The combination, in a triple-expansion engine, of a large cylinder, C, supported upon the bed, and two smaller cylinders, one at each end of cylinder C and axially in line therewith and supported wholly thereby, substantially as described.

2. The combination ofthe cylinder C, cylinder F, supported by one head of said cylinder, and a third cylinder connected by a bracket with the other head of thc cylinder C, snbstantially as described.

3. A triple-expansion directaeting engine provided with three cylinders axially in line, the pistons of the center and forward engines connected by independent rods with the crosshead,and the rear and higlrpressnre cylinder connected with the piston ot' the center cylinder, substantially as described.

4. The combination ot' the three axially-arranged cylinders with valves, one connected to be operated from a moving part of the engine,and connections between the other valves constructed to vary the throws of the valves, substantially as described.

In testimony whereofl have signed my name to this specification in the presence of two subscribing witnesses. f'

MARSHALL T. DAVIDSON.

W'itnesses:

G. XV. BAiRD, Gmo. II. GRAHAM. 

